This invention relates generally to semiconductor devices, and more specifically, to semiconductor devices for use in memory cells.
In SONOS (silicon-oxide-nitride-oxide-silicon) based non-volatile memory (NVM) cells, hot-carrier electron injection (HCI) into the nitride may be used to program a memory cell having a high threshold voltage (Vt) state and a low Vt state. Efficient HCI programming requires high channel region doping and a sharp drain junction; however, read disturb is aggravated by having high channel region doping. That is, the repeated reading of a memory cell in the low Vt state continuously increases the Vt of the memory cell. The Vt may increase to a point where the state of the memory cell may change from a low Vt state to a high Vt state, thus resulting in a reliability failure of the memory cell. Therefore, a need exists for a memory cell with increased reliability during repeated reads.